My first Through-the-Wall construction with a 3-layer sandwich fin for each of three fin. All yellow, with a black accent wing.  Flies extremely well on a D12-5  but  also have done an E9-6.  Make certain the parachute is un-melted and wrapped correctly, with sufficient Dog Barf wadding to protect it!  It's a long ways down!  (My largest and most fun rocket to date!)